A, B = input().split()
S = '0' + A + B + '+'
# print(S)
ans = 0; temp = 0
pos = True
for c in S:
	if c in ['+', '-']:
		if pos:
			ans += temp			
		else:
			ans -= temp
		temp = 0
		pos = c == '+'
	else:
		temp = 10 * temp + int(c)
print(ans)